Every aircraft needs an annual inspection. Mechanics spend hours with the hassle of figuring out whether any FAA Airworthiness Directive (another site, opens in a new tab) applies to that aircraft. Comparing ADs with aircraft data (another site, opens in a new tab) is cumbersome and prone to errors.
Here are the top ten traps to look out for:
1. A dozen spellings for one engine
An AD says O-200-A, but the registry says “0-200 SERIES”, with a zero, not the letter O.
More than 8,000 registered aircraft have an engine written with a zero.
2. “Series” means two different things
In an AD, “737-800 series” means the 737-823 and the 737-8H4. In the registry, “O-200 SERIES” means “we don’t know which variant”.
More than 180,000 registered aircraft have a model or engine named only by its family.
3. Most ADs hang on something the registry doesn’t know
Think of “equipped with P/N 0322709”, “modified per STC SA64CH”, “with 25 or more hours”.
Almost 10,000 ADs in force have a condition like this.
4. “As listed in Service Bulletin…”
More than 4,000 ADs don’t say which aircraft they cover.
They point to a service bulletin you then have to find and read.
5. The AD may have been rewritten
653 ADs in force are really a later revision, and 13 revisions don’t revise at all: they rescind the AD entirely.
Read the original and you’re reading the wrong rule.
6. Parts ADs are invisible
Magnetos, carburetors, oil filter adapters, avionics: the registry never records what’s installed.
426 ADs are about parts that could be on your airplane, or not.
7. Slashes are shorthand
“207A/T207A” means two models. “L/TSIO-520” means the TSIO-520 and the LTSIO-520.
About 300 ADs write models this way.
8. Serial numbers aren’t always serial numbers
“Line numbers 1 through 500” are Boeing line numbers, not the serial on the data plate.
“Except S/N 1” means every serial but one. “27-1 and up” has no end.
9. The index is broader than the AD
The FAA files each AD (another site, opens in a new tab) under the makes and models it might touch.
You must read them to see if your aircraft is ruled out by serial number.
10. Superseded ADs don’t disappear
More than 2,000 ADs in force replace older ones.
The old ones still show up in logbook entries, and still need to be tracked.